It is known to adjust the angle of inclination of the backrest using a hand wheel or an electric motor. A rotational movement produced in this way is transmitted to the backrest via a step-down gear that is formed by a wobble mechanism in most cases.
With conventional vehicle seats there is the risk in the event of a rear end collision, owing to the relatively pronounced flexibility of the backrest cushioning for comfort requirements, that the vehicle occupant will slide up along the backrest. In particular, if the headrest is adjusted too low, the headrest acts only as a slight restraint, resulting in over-stretching of the back of the neck and excessive straining of the back of the neck and resultant injuries to the cervical vertebra.